Antibiotic LL-E19085

ABSTRACT

This disclosure describes novel antibacterial agents designated LL-E10985 alpha , LL-E19085 beta , LL-E19085 gamma , LL-E19085 gamma and LL-E19085 zeta , having the structure:   &lt;IMAGE&gt;   their production by aerobic fermentation of a new subspecies of Micromonospora citrea NRRL 18351 and mutants thereof, and the isolation and purification thereof.

This application is a continuation-in-part of application Ser. No. 07/373,357 filed June 29, 1989, now abandoned which is a continuation-in-part of application Ser. No. 07/179,357 filed Apr. 8, 1988, now abandoned.

SUMMARY OF THE INVENTION

This invention relates to new antibacterial agents designated LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ and LL-E19085η, to their production by fermentation, to methods for their recovery and concentration from crude solutions and to processes for their purification. The present invention includes within its scope the antibacterial agents in dilute form, as crude concentrates and in pure form. The effect of these new agents on specific microorganisms, together with their chemical and physical properties, differentiate them from previously described antibacterial agents. The structure of antibiotic LL-E19085 is as follows:

    ______________________________________                                          ##STR2##                                                                      E19085       R1               R2                                               ______________________________________                                         α      COCH.sub.2 CH(CH.sub.3).sub.2                                                                   CH.sub.3                                         β       COCH(CH.sub.3).sub.2                                                                            CH.sub.3                                         γ      COCH.sub.3       CH.sub.3                                         ζ       COCH.sub.2 CH(CH.sub.3).sub.2                                                                   H                                                η        H                CH.sub.3                                         ______________________________________                                    

The physiochemical characteristics of antibiotic LL-E19085α are as follows:

a) Molecular formula: C₃₆ H₃₁ NO₁₂ ;

b) Molecular weight: 669 FABMS (M+3H)⁺ =M/Z 672.21176;

c) Elemental Analysis: C, 64.55; H, 4.46; N, 1.92;

d) Specific rotation: [α]_(D) ²⁶ =-52° (C, 1.11%--dichloromethane);

e) Ultraviolet absorption spectra:

λmax nm ε 0.1N HCl=224 nm (27,700), 255 nm (21,900), 328 nm (16,400), 420 nm (4,230)

λmax nm ε 0.1N NaOH=217 nm (76,100), 340 nm (15,100), 399 nm (12,900)

λmax nm ε CH₃ OH=222 nm (38,200), 240 nm (30,100), 255 nm (30,100), 321 nm (24,500), 384 nm (8,050)

f) infrared absorption spectrum: (KBr disk), max (cm⁻¹) 1800, 1742, 1690, 1621, 1422, 1273;

g) Proton magnetic resonance spectrum: (CDCl₃) shows significant peaks as follows:

    ______________________________________                                         δ   #H            M     J (Hz)                                           ______________________________________                                         13.47     1             s     --                                               8.20      1             d     8.5                                              7.92      1             d     8.5                                              7.58      1             s     --                                               7.19      1             s     --                                               7.09      1             s     --                                               4.78      1             d     11.6                                             4.45      1             d     11.6                                             4.02      3             s     --                                               3.99      3             s     --                                               3.48      1             d     12.8                                             3.35      1             d     12.8                                             2.21      2             d     6.8                                              2.10      1             m     --                                               1.83      3             s     --                                               1.80      3             s     --                                               0.955     6             d     6.48                                             ______________________________________                                    

h) Carbon-13 nuclear magnetic resonance spectrum: (CDCl₃) shows significant peaks as follows:

    ______________________________________                                         δ M         δ                                                                               M       δ                                                                             M                                        ______________________________________                                         181.2   s         134.8  s       65.0 t                                        178.1   s         132.1  d       62.3 s                                         172.1* s         129.7  s       56.8 q                                        171.5   s         124.4  d       56.5 q                                        165.8   s         120.8  s       42.9 t                                        162.1   s         119.9  s       41.9 t                                        155.5   s         119.5  s       25.8 q                                        153.4   s         117.7  d       25.5 d                                        150.8   s         107.3  s       22.4 q                                        148.7   s         104.9  d       22.3 q                                        140.7   s         100.4  d       20.2 q                                        137.7   s          93.4  s                                                     ______________________________________                                          *Two superimposed resonances.                                            

The physiochemical characteristics of antibiotic LL-E19085β are as follows:

a) Molecular formula: C₃₅ H₂₉ NO₁₂ ;

b) Molecular weight: 655;

c) Ultraviolet absorption spectra: λmax (CH₃ CH/0.05M pH 4.5 NH₄ OAC 3/2) 258 nm, 325 nm, 385 nm;

d) Infrared absorption spectra: λmax (cm⁻¹) 3434 br, 2924, 1804, 1752, 1693, 1621, 1426, 1272;

e) Proton nuclear magnetic resonance spectrum: CDCl₃ shows significant peaks as follows:

    ______________________________________                                         δ  #H           M       J (Hz)                                           ______________________________________                                         13.50    1            br      --                                               8.26     1            d       8.5                                              7.94     1            d       8.5                                              7.66     1            s       --                                               7.21     1            s       --                                               7.14     1            s       --                                               4.77     1            d       11.6                                             4.47     1            d       11.6                                             4.04     3            s       --                                               4.02     3            s       --                                               3.50     1            d       14.8                                             3.36     1            d       14.8                                             2.55     1            septet  7.0                                              1.83     3            s       --                                               1.77     3            s       --                                               1.19     3            d       7.0                                              1.18     3            d       7.0                                              ______________________________________                                    

f) HPCL* retention time: 2.4 minutes.

The physiochemical characteristics of antibiotic LL-E19085γ are as follows:

a) Molecular formula: C₃₃ H₂₅ NO₁₂ ;

b) Molecular weight: 627

c) Ultraviolet absorption spectra: λmax (CH₃ CN/0.05M pH 4.5 NH₄ OAC 3/2) 258 nm, 325 nm, 385 nm;

d) Infrared absorption spectra: λmax (KBr) cm⁻¹ : 3433 br, 2925, 1805, 1745, 1694, 1621, 1426, 1272;

e) Proton nuclear magnetic resonance spectrum: CDCl₃ shows significant peaks as follows:

    ______________________________________                                         δ   #H            M     J (Hz)                                           ______________________________________                                         13.46     1             br    --                                               8.26      1             d      8.6                                             7.94      1             d      8.6                                             7.66      1             s     --                                               7.21      1             s     --                                               7.14      1             s     --                                               4.81      1             d     11.5                                             4.43      1             d     11.5                                             4.04      3             s     --                                               4.02      3             s     --                                               3.50      1             d     14.9                                             3.36      1             d     14.9                                             2.10      3             s     --                                               1.82      3             s     --                                               1.75      3             s     --                                               ______________________________________                                    

f) HPLC* retention time: 1.6 minutes.

The physiochemical characteristics of antibiotic LL-E19085ζ are as follows:

a) Molecular formula: C₃₅ H₂₉ NO₁₂ ;

b) Molecular weight: 655;

c) Ultraviolet absorption spectra: λmax (CH3CH/0.05M pH 4.5 NH₄ OAC3/2): 258 nm, 324 nm, 380 nm, 420 nm;

d) Infrared absorption spectrum: (KBr) λmax (Cm⁻¹) 3429 (br), 2960, 1805, 1745, 1693, 1626, 1421, 1279;

e) Proton nuclear magnetic resonance spectrum: CDCl₃

    ______________________________________                                         δ  #H           M       J (Hz)                                           ______________________________________                                         13.45    1            s       --                                               8.22     1            d       8.5                                              7.91     1            d       8.5                                              7.75     1            s       --                                               7.26     1            s       --                                               7.14     1            s       --                                               6.20     1            br      --                                               4.76     1            d       11.5                                             4.45     1            d       11.5                                             4.06     3            s       --                                               3.48     1            d       14.8                                             3.35     1            d       14.8                                             2.20     2            d       6.6                                              2.10     1            septet  6.6                                              1.81     3            s       --                                               1.75     3            s       --                                               .950     6            d       6.6                                              ______________________________________                                    

f) Carbon 13 nuclear magnetic resonance spectra:

    ______________________________________                                                 δ                                                                             δ                                                           ______________________________________                                                 181.4                                                                               119.7                                                                     178.0                                                                               119.6                                                                     172.8                                                                               117.7                                                                     171.7                                                                               108.4                                                                     171.6                                                                               107.1                                                                     165.6                                                                               100.2                                                                     161.6                                                                                93.4                                                                     154.7                                                                                64.9                                                                     153.5                                                                                62.3                                                                     150.2                                                                                56.5                                                                     146.3                                                                                42.8                                                                     140.5                                                                                41.7                                                                     137.5                                                                                25.6                                                                     134.6                                                                                25.4                                                                     132.2                                                                                22.2*                                                                    129.7                                                                                20.0                                                                     124.2                                                                          120.1                                                                  ______________________________________                                          *two superimposed signals                                                

g) HPLC* retention time: 1.9 minutes

The physiochemical characteristics of antibiotic LL-E19085η are as follows:

a) Molecular formula: C₃₁ H₂₃ NO₁₁ ;

b) Molecular weight: 585 HRFABMS: (M+3H)⁺ =M/Z 588.1479;

c) Specific rotation: [α]_(D) ^(26o) =-63° (C 0.19)DMSO;

d) Ultra violet absorption spectrum: λmax (MeOH/CH₂ CL₂ 1:1) 223 (37,800), 321 (21,700), 302 (21,750);

e) Infrared absorption spectrum: (KBr) λmax CM⁻¹ 3437 (br), 2923, 1798, 1691, 1623, 1427, 1276;

f) Proton nuclear magnetic resonance spectrum: (CDCl₃ DMSO d₆)

    ______________________________________                                         δ  #H            M      J (Hz)                                           ______________________________________                                         8.24     1             d       8.5                                             7.96     1             d       8.5                                             7.63     1             s      --                                               7.23     1             s      --                                               7.17     1             s      --                                               5.28     1             br     --                                               4.33     1             brd    10.1                                             4.04     3             s      --                                               4.02     3             s      --                                               3.90     1             brd    10.1                                             3.51     1             d      14.7                                             3.37     1             d      14.7                                             1.77     3             s      --                                               1.71     3             s      --                                               ______________________________________                                    

g) Carbon 13 nuclear magnetic resonance spectrum: (CMSO D₆ /CDCl₃)

    ______________________________________                                                 δ                                                                             δ                                                           ______________________________________                                                 180.9                                                                               107.4                                                                     177.7                                                                               104.4                                                                     173.0                                                                               100.7                                                                     171.9                                                                                93.3                                                                     165.8                                                                                65.8                                                                     161.4                                                                                63.4                                                                     155.6                                                                                56.7                                                                     153.8                                                                                56.1                                                                     150.8                                                                                41.4                                                                     148.6                                                                                25.3                                                                     140.3                                                                                19.0                                                                     137.3                                                                          135.2                                                                          132.2                                                                          129.6                                                                          123.9                                                                          120.2                                                                          119.3                                                                          119.2                                                                          117.6                                                                  ______________________________________                                    

h) HPLC* retention time: 1.2 minutes

DETAILED DESCRIPTION OF THE INVENTION

The antibacterial agents LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ and LL-E19085η are produced by aerobic fermentation of microbial culture LL-E19085 which is a natural selection isolate of a culture isolated from a soil sample collected in Manyara, Tanzania. The culture was taxonomically characterized and identified as a new subspecies of Micromonospora citrea.

This new subspecies is maintained in the culture collection of the Medical Research Division, American Cyanamid Company, Pearl River, N.Y. as culture number LL-E19085. A viable culture of this new microorganism has been deposited with the ARS Culture Collection, Fermentation Laboratory, Northern Regional Research Center, U.S. Department of Agriculture, 1815 North Univeristy Street, Peoria, Ill. 61604 and has been added to its permanent collection. It has been assigned the strain designation NRRL 18351 by such depository. Access to such culture, under strain designation NRRL 18351, during pendency of the instant application shall be available to one determined by the Commissioner of Patents and Trademarks to be entitled thereto under 37 C.F.R. Section 1.14 and 35 U.S.C. Section 122, and all restrictions on availability to the public of such culture will be irrevocably removed upon grant of a patent on the instant application.

Observations were made of the cultural, physiological and morphological features of culture LL-E19085 using methods well known in the art. The generic assignment of LL-E19085 to the genus Micromonospora was confirmed morphologically and chemically. The strain produced monospores on the vegetative hyphae. No aerial hyphae were observed. Electron microscopic examination showed that the spores were warty. Whole cell analysis showed that LL-E19085 contained the meso isomer as well as traces of the L isomer of diaminopimelic acid. This strain showed the presence of xylose plus traces of arabinose in its whole cell sugar hydrolysates. Therefore LL-E19085 is considered to be a subspecies of Micromonospora citrea.

Comparative data on the morphology of LL-E19085 is given in Tables I and II. Physiological data is given in Tables III and IV.

                  TABLE I                                                          ______________________________________                                         ISP Agar                           Soluble                                     Medium   Spores     Vegetative Mycelium                                                                           Pigments                                    ______________________________________                                         Yeast-Malt                                                                              Slight, black                                                                             Strong orange (50)                                                                            Slight,                                     (ISP 2)  at edge    to medium orange-                                                                             brown-                                                          yellow (71*)   black                                       Oatmeal  None       Light orange-yellow                                                                           Slight,                                     (ISP 3)             (70) to vivid  brownish                                                        orange-yellow (66)                                         Inorganic                                                                               None       Light orange-yellow                                                                           Slight,                                     Salts-Starch        (70) to vivid  brownish                                    (ISP 4)             orange-yellow (66)                                         Glycerol-                                                                               Slight,    Light tone of  Slight,                                     Asparagine                                                                              brownish at                                                                               brownish-orange                                                                               brownish                                    (ISP 5)  edge       (54)                                                       ______________________________________                                          *Parenthetical numbers are colors taken from Kelly, K. L. and Judd, D. B.      Color. Universal Language and Dictionary of Names, Nat. Bur. Stand.            (U.S.), Spec. Publ. 440, 1976, Washington, D.C. and the accompanying           InterSociety Color Council, National Bureau of Standards Centroid Color        Charts.                                                                  

                  TABLE II                                                         ______________________________________                                         Agar Medium  Actinomycete Growth (28° C., 2 weeks)                      ______________________________________                                         Pablum       Brown vegetative hyphae. Sparse                                                spores. Soluble dark brown pigment.                               Yeast Czapek's                                                                              Brownish tan vegetative hyphae.                                                Sparse spores. Slight soluble                                                  dark-brownish pigment.                                            Czapek's     Vegetative hyphae covered/spores.                                              Black spores. Slight dark pigment.                                Yeast Extract-                                                                              Black spores, Dry soluble brownish                                Dextrose     pigment.                                                          Nutrient     Orange-brown vegetative hyphae.                                                Sparse black spores. Moderate                                                  brown pigment.                                                    Nutrient Glycerol                                                                           Blackish-tan vegetative hyphae.                                                Sparse spores. Intense brown-black                                             pigment.                                                          Bennett's Dextrin                                                                           Tan vegetative hyphae. Moderate                                                black spores. Soluble reddish-brown                                            pigment.                                                          Glucose Asparagine                                                                          Orange-tan vegetative hyphae. No                                               spores. Slight soluble dark pig-                                               ment.                                                             ______________________________________                                    

                  TABLE III                                                        ______________________________________                                                        Carbohydrate                                                    Carbohydrate   Utilization                                                     ______________________________________                                         Arabinose      +                                                               Cellulose      -                                                               Fructose       ±                                                            Glucose        +                                                               Inositol       -                                                               Mannitol       -                                                               Raffinose      -                                                               Rhamnose       -                                                               Sucrose        ±                                                            Xylose         +                                                               ______________________________________                                    

                  TABLE IV                                                         ______________________________________                                                          Physiological                                                 Gordon Test      Reaction                                                      ______________________________________                                         Hydrolysis of                                                                  Casein           +                                                             Xanthine         -                                                             Hypoxanthine     -                                                             Tyrosine         +                                                             Adenine          +                                                             Gelatin          +                                                             Potato Starch    +                                                             Esculin          +                                                             Physiological                                                                  Production of                                                                  Nitrate Reductase                                                                               -                                                             Phosphatase      +                                                             Urease           -                                                             Growth on                                                                      Salicin          -                                                             5% Sodium Chloride                                                                              -                                                             Lysozyme Broth   -                                                             Decarboxylation of                                                             Acetate          +                                                             Benzoate         -                                                             Citrate          -                                                             Lactate          +                                                             Malate           -                                                             Mucate           -                                                             Oxalate          -                                                             Propionate       +                                                             Pyruvate         +                                                             Succinate        -                                                             Tartrate         -                                                             Acid from                                                                      Adonitol         -                                                             Arabinose        +                                                             Cellobiose       +                                                             Dextrin          +                                                             Dulcitol         -                                                             Erythritol       -                                                             Fructose         +                                                             Galactose        +                                                             Glucose          +                                                             GLycerol         +                                                             Inositol         -                                                             Lactose          +                                                             Maltose          +                                                             Mannitol         -                                                             Mannose          +                                                             α-Methyl-D-glucoside                                                                      +                                                             Melibiose        +                                                             Raffinose        +                                                             Rhamnose         -                                                             Salicin          +                                                             Sorbitol         -                                                             Sucrose          +                                                             Trehalose        +                                                             Xylose           +                                                             β-Methyl-D-xyloside                                                                        -                                                             Growth at                                                                      10° C.    -                                                             42° C.    +                                                             45° C.    +                                                             ______________________________________                                          + = positive; - = negative                                               

It is to be understood that for the production of the new antibacterial agents LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ and LL-E19085η, the present invention is not limited to this particular organism or to organisms fully answering the above growth and microscopic characteristics, which are given for illustrative purposes only. In fact it is desired and intended to include the use of mutants produced from this organism by various means such as exposure to x-radiation, ultraviolet radiation, N'-methyl-N'-nitro-N-nitrosoguanidine, actinophages and the like.

The in vitro antibacterial effects of antibiotics LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ and LL-E19085η were determined by standard agar dilution methods against clinical isolates obtained from medical centers representing various geographical areas in the United States. The inoculum of each culture was approximately 1 to 5×10⁴ colony forming units applied with a Steers multiple inocula replicator to plates containing the antibiotic in Mueller-Hinton agar. The agar was supplemented with about 5% sheep blood where required for the growth of the organism. The results are given in Tables V and VI.

                  TABLE V                                                          ______________________________________                                         In vitro Antibacterial Activity of LL-E19085α                                                    Minimal                                                                        Inhibitory                                                                     Concentration                                          Organism                (mcg/ml)                                               ______________________________________                                         Staphylococcus aureus                                                                           ATCC 25923 0.12                                               Staphylococcus aureus                                                                           Smith      0.12                                               Staphylococcus aureus                                                                           VGH 84-45  ≦0.06                                       Staphylococcus aureus                                                                           CMC 83-127 ≦0.06                                       Staphylococcus aureus                                                                           CMC 83-131 ≦0.06                                       Staphylococcus aureus                                                                           CMC 83-132 ≦0.06                                       Staphylococcus aureus                                                                           SSC 82-57  ≦0.06                                       Staphylococcus epidermidis                                                                      IO 83-58   ≦0.06                                       Staphylococcus saphrophiticus                                                                   VGH 84-50  ≦0.06                                       Streptococcus β-hemolyticus                                                                C 203      ≦0.06                                       Streptococcus β-hemolyticus                                                                VGH 84-60  ≦0.06                                       Streptococcus β-hemolyticus                                                                VGH 84-61  ≦0.06                                       Streptococcus β-hemolyticus                                                                VGH 84-62  ≦0.06                                       Streptococcus pneumoniae                                                                        SV-1       ≦0.06                                       Streptococcus pneumoniae                                                                        K 84-21    ≦0.06                                       Enterococcus     VGH 84-65  ≦0.06                                       Enterococcus     VGH 84-68  ≦0.06                                       Enterococcus     IO 83-28   ≦0.06                                       Enterococcus     IO 83-40   0.12                                               Enterococcus     CMC 83-72  ≦0.06                                       Escherichia coli No. 311    >128                                               Klebsiella pneumoniae                                                                           AD         >128                                               Enterobacter cloacae                                                                            VGH 84-37  >128                                               Morganella morganii                                                                             VGH 84-11  >128                                               Serratia marcescens                                                                             K 84-14    >128                                               Pseudomonas aeruginosa                                                                          12-4-4     >128                                               Citrobacter diversis                                                                            MOR 84-3   >128                                               Proteus vulgaris CMC 84-35  >128                                               Alcaligenes ssp. ISG 86-34  >128                                               erratia rubidea  UHL 86-4   >128                                               Bacteroides fragilis                                                                            ATCC 25285 16                                                 Bacteroides vulgaris                                                                            ATCC 29327 ≦0.06                                       Bacteroides theta                                                                               ATCC 29741 4                                                  Bacteroides theta                                                                               ATCC 29742 4                                                  Clostridium perfringen                                                                          ATCC 13124 ≦0.06                                       Clostridium differensis                                                                         ATCC 17858 ≦0.06                                       Peptococcus magnus                                                                              ATCC 29328 ≦0.06                                       Peptococcus magnus                                                                              ATCC 14956 ≦0.06                                       Peptococcus asacrolytis                                                                         ATCC 29743 ≦0.06                                       Escherichia coli ATCC 25922 >128                                               Staphylococcus aureus                                                                           ATCC 29213 ≦0.06                                       ______________________________________                                    

                                      TABLE VI                                     __________________________________________________________________________     Invitro Antibacterial Activity of LL-E19085β,γ,δ,η                                Minimal Inhibitory Concentration (mcg/ml)              Organism                LL-E19085                                                                            LL-E19085                                                                            LL-E19085                                                                            LL-E19085                            __________________________________________________________________________     Staphylococcus aureus                                                                       NEMC 87-69 4     4     8     ≦.015                         Staphylococcus aureus                                                                       ROSE (MP)  2     1     2     ≦.015                         Staphylococcus aureus                                                                       IVES 542   4     8     8     ≦.015                         Staphylococcus hemolyticus                                                                  AVAH 88-1  2     8     4     ≦.015                         Staphylococcus hemolyticus                                                                  AVAH 88-3  4     0.5   2     ≦.015                         Bacteroides cereus                                                                          DAVIES     2     0.5   2     ≦.015                         Streptococcus faecalis                                                                      ARUM 87-41 2     0.5   2     ≦.015                         Enterococcus CHBM 88-60 2     0.5   2     ≦.015                         Enterococcus Grp D WRVA 88-33                                                                          2     0.5   2     ≦.015                         Streptococcus faecalis                                                                      VCI 85-30  2     .06   2     ≦.015                         Streptococcus faecalis                                                                      VCH 84-69  2     .03   2     ≦.015                         Streptococcus faecalis                                                                      CMC 83-120 2     1     2     ≦.015                         Streptococcus a-hemolyticus                                                                 AMCH 88-84 0.5   ≦.008                                                                         1     ≦.015                         Streptococcus b-hemolyticus                                                                 AMCH 88-86 2     ≦.008                                                                         2     ≦.015                         Streptococcus pneumoniae                                                                    CHBM 88-70 .25   ≦.008                                                                         .12   ≦.015                         Streptococcus pneumoniae                                                                    CHBB 88-75 .12   ≦.008                                                                         .12   ≦.015                         Streptococcus pneumoniae                                                                    TEX 85-2   .12   ≦.008                                                                         .12   ≦.015                         Staphylococcus aureus                                                                       ATCC 29213 2     1     2     ≦.015                         Klebsiella pneumoniae                                                                       NEMC 87-271                                                                               ≧64                                                                           ≧16                                                                           ≧32                                                                           ≧32                           Escherichia coli                                                                            D21        ≧64                                                                           ≧16                                                                           ≧32                                                                           ≧32                           Escherichia coli                                                                            D22        8     16    32    2                                    Escherichia coli                                                                            ATCC 25922 >64   >16   >32   >32                                  Escherichia coli                                                                            ATCC 35218 >64   >16   >32   >32                                  Staphylococcus aureus                                                                       ATCC 25923 0.5   ≧0.008                                                                        1     ≦0.015                        Staphylococcus aureus                                                                       VGH 84-47  4     1     4     ≦0.015                        Staphylococcus aureus                                                                       K82-26     2     ≦0.008                                                                        2     ≦0.015                        Staphylococcus aureus                                                                       CMC 83-131 4     16    8     0.12                                 __________________________________________________________________________

When the compounds are employed for the above utility, they may be combined with one or more pharmaceutically acceptable carriers, for example solvents, diluents and the like, and may be administered parenterally in the form of sterile injectable solutions or suspensions containing from about 0.05 to 5% suspending agent in an isotonic medium. Such pharmaceutical preparations may contain, for example, from about 0.05 up to about 90% of the active ingredient in combination with the carrier, more usually between about 5% and 60% by weight.

The effective dosage of active ingredient employed may vary depending on the particular compound employed, the mode of administration and the severity of the condition being treated. However, in general, satisfactory results are obtained when the compounds of the invention are administered at a daily dosage of from about 2 to about 100 mg/kg of animal body weight, preferably given in divided doses two to four times a day, or in substained release form. For most large mammals the total daily dosage is from about 100 to 750 mg, preferably from about 100 to 500 mg. Dosage forms suitable for internal use comprise from about 100 to 750 mg of the active compound in intimate admixture with liquid pharmaceutically acceptable carrier. This dosage regimen may be adjusted to provide the optimal therapeutic response, for example, several divided doses may be administered daily or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation.

These active compounds may be administered by intravenous, intramuscular, or subcutaneous routes. Liquid carriers include sterile water, polyethylene glycols, non-ionic surfactants and edible oils such as corn, peanut and sesame oils, as are appropriate to the nature of the active ingredient and the particular form of administration desired. Adjuvants customarily employed in the preparation of pharmaceutical compositions may be advantageously included, such as preserving agents, and antioxidants, for example, vitamin E, ascorbic acid, BHT and BHA.

The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils.

GENERAL FERMENTATION CONDITIONS

Cultivation of Micromonospora citrea sp. LL-E19085 may be carried out in a wide variety of liquid culture media. Media which are useful for the production of antibiotic LL-E19085α include an assimilable source of carbon, such as starch, sugar, molasses, glycerol, etc.; an assimilable source of nitrogen, such as protein, protein hydrolysate, polypeptides, amino acids, cornsteep liquor, etc.; and inorganic anions and cations, such as potassium, sodium, ammonium, calcium, sulfate, carbonate, phosphate, chloride, etc. Trace elements such as boron, molybdenum, copper, etc., are supplied as impurities of other constituents of the medium. Aeration is supplied by forcing sterile air through or onto the surface of the fermenting medium. Agitation is provided by a mechanical impeller. An antifoam agent may be added as needed. The growth of the organism is usually conducted at about 24°-37° C., preferably at about 28° C.

The following examples describe the invention in detail.

EXAMPLE 1 Inoculum Preparation

A typical medium used to grow the inocula was prepared according to the following formula:

Dextrose: 1.0%

Dextrin: 2.0%

Yeast extract: 0.5%

NZ Amine A *: 0.5%

Calcium carbonate: 0.1%

Defoam agent: 0.3%

Water qs: 100%

This medium was sterilized and a 100 ml portion in a 500 ml flask was inoculated with mycelial scrapings from an agar slant of the culture Micromonospora citrea sp LL-E19085. The inoculated flask was then placed on a rotary shaker and agitated vigorously for approximately 48 hours at 32° C., providing primary inoculum.

A 100 ml portion of this primary inoculum was then used to inoculate 10 liters of the above sterile medium which was incubated at 32° C. with aeration for 72 hours, providing secondary inoculum.

A 10 liter portion of this secondary inoculum was then used to inoculate 260 liters of the above sterile medium in a tank. This medium was incubated at 32° C. with agitation by an impeller driven at 180 rpm, a sterile air flow of 200 liters per minute and the addition of 50 ml of a defoaming agent for about 48 hours, providing tertiary inoculum.

EXAMPLE 2 Fermentation

A fermentation medium was prepared according to the following formulation:

Dextrin: 3.0%

Dextrose: 0.5%

Nutrisoy: 1.5%

Corn steep liquor: 0.5%

Calcium carbonate: 0.5%

Defoam agent: 0.3%

Water qs: 100%

A 2800 liter portion of the above medium in a tank was sterilized and then inoculated with 300 liters of tertiary inoculum prepared as described in Example 1. Aeration was supplied at the rate of 6.5 liters of sterile air per liter of mash per minute and agitation was supplied by an impeller driven at about 110 rpm. The temperature was maintained at 28° C. and defoaming agent was added as required. The fermentation was terminated after 129 hours.

EXAMPLE 1 Isolation of Antibiotic LL-E19085α

A 1500 liter portion of the whole harvest mash, prepared as described in Example 2, was mixed with 15 liters of toluene for 30 minutes, then 250 lb of diatomaceous earth was added. After mixing for 15 minutes this mixture was filtered and the cake washed with 150 liters of water. The cake was slurried in a mixture of 208 liters of acetone, 416 liters of dichloromethane and 20 liters of 1.5N hydrochloric acid for 2 hours and then filtered. The cake was washed with about 175 liters of dichloromethane with the wash and filtrate combined. The cake was then washed with about 800 liters of water and this wash also combined with the above wash and filtrate and mixed. The dichloromethane layer was separated and washed with an equal volume of water. The dichloromethane layer was separated and concentrated to 100 liters, reextracted with fresh methylene chloride if any aqueous phase was present, and finally concentrated to about 1-3 liters.

The dichloromethane extracts were triturated repeatedly, first with hexane:dichloromethane (9:1) and then with hexane alone to remove the bulk of the fatty impurities giving a brown powder.

Several such partially purified preparations, from fermentations conducted as described in Example 2, totaling 20 g and averaging 10-30% LL-E19085α, were combined and purified by reverse-phase chromatography. The column consisted of a 15 liter bed of C₁₈ bonded phase packing of 40 micron particle size. The charge was loaded onto the column in 500 ml of acetonitrile:tetrahydrofuran (1:1). The column was developed at a flow rate of 1.0 liter per minute with a mobile phase consisting of acetonitrile:0.1M pH 4.5 ammonium acetate buffer (8.2). Fractions were collected at approximately 12 minute intervals. Fractions 6 and 7 were combined and evaporated, giving 2.7 g of pure LL-E19085α having the characteristics disclosed in the hereinabove specification.

EXAMPLE 4 Isolation of Antibiotics LL-E19085β and LL-E19085γ

These minor components were isolated from various side fractions derived from the refining of LL-E19085α from tank fermentations. Chromatography of the material from methylene chloride (CH₂ Cl₂), extraction of the whole mash on silica gel, and eluting with mixtures of acetone in CH₂ Cl₂ yielded a fraction enriched in β and γ. This material was dissolved in acetonitrile (ACN) and separated by reversed phase chromatography, NB 7411C99. The column was 21.4 mm×25 mm packed with C₁₈ bonded silica. The column was eluted with 60% ACN, 40% 0.05M pH 4.5 NH₄ OAc. Fractions were combined on the basis of analytical hplc to yield β and γ.

EXAMPLE 5 Isolation of Antibiotic LL-E19085η

An early fraction from he large-scale C₁₈ column used to purify E19085α was used to obtain the η component. The material was dissolved in ACN and separated on the 21.4 mm×25 cm C₁₈ column eluting with 50% ACN, 50% 0.05M pH 4.5 NH₄ OAc. Fractions were combined on the basis of analytical hplc to yield E19085η.

EXAMPLE 6 Isolation of LL-E19085ζ

Side fractions from silica gel purification of E19085α were enriched in E19085ζ (NB7411C73). The fraction containing zeta was rechromatographed on silica gel (150 g Wolen, column 2.5×50 cm) eluted with Ch₂ Cl₂ followed by 5% acetone 95% CH₂ Cl₂. Fractions were combined on the basis of analytical hplc and evaporated to dryness to yield E19085ζ. (7580C151) 

We claim:
 1. The antibiotic LL-E19085α, an antibacterial agent, of the formula: ##STR3## wherein R₁ is COCH₂ CH(CH₃)₂ and R₂ is CH₃.
 2. The antibiotic LL-E19085β of the formula: ##STR4## wherein R₁ is COCH(CH₃)₂ and R₂ is CH₃.
 3. The antibiotic LL-E19085γ, of the formula: ##STR5## wherein R₁ is COCH₃ and R₂ is CH₃.
 4. The antibiotic LL-E19085ζof the formula: ##STR6## wherein R₁ is COCH₂ CH(CH₃)₂ and R₂ is H.
 5. The antibiotic LL-E19085η of the formula: ##STR7## wherein R₁ is H and R₂ is CH₃.
 6. A pharmaceutical composition comprising an antibacterially effective amount of a compound of any one of claims 1, 2, 3, 4 or 5 in association with a pharmaceutically acceptable carrier.
 7. A method of treating bacterial infections in warm-blooded animals which comprises administering to said animals an antibacterially effective amount of a compound selected from the group consisting of LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ, and LL-E19085η.
 8. A process for producing an antibiotic selected from the group consisting of LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ, and LL-E19085η which comprises aerobically fermenting the microorganism Micromonospora citrea sp. NRRL 18351 or mutants thereof which produce said antibiotic in a liquid medium containing assimilable sources of carbon, nitrogen and inorganic salts, until substantial antibiotic activity is imparted to said medium and then recovering said antibiotic therefrom.
 9. The process for producing antibiotics LL-E19085α, LL-E19085β, LL-E19085γ, LL-E19085ζ, and LL-E19085η as recited in claim 8, which comprises aerobically fermenting a liquid medium containing assimilable sources of carbon, nitrogen and inorganic salts, which medium has been inoculated with a viable culture of the microorganism Micromonospora citrea sp. NRRL 18351 or mutants thereof, which produce said antibiotic maintaining said fermentation culture at a temperature of about 24°-37° C. for a period of 50-150 hours, harvesting the mash and extracting said antibiotic. 